Whooper swans winter on Swan Lake in Altai Territory MOSCOW, 3 Jan. In the Altai Territory, a crowd of tourists collapsed under the cracked ice on Lake Svetly. The local media drew attention to the incident. According to an eyewitness of the incident, quoted by the city group «Incident Barnaul» on VKontakte, people found themselves on the ice because of an attempt to bypass the queue at the observation deck. There is no official confirmation of this information. The moment of the fall was recorded on video by a drone of one of the visitors. There is no data on the victims yet. Lake Svetloe, also called Swan Lake, is known for the birds that fly here for wintering. 
named the safe thickness of ice on water bodies
